Buckle closure for plastic strapping

ABSTRACT

A buckle used as a strapping closure includes two parallel tapered prongs holding the strap. The prongs have adjacent open ends while their other ends are firmly connected to a curved gusset. The gusset is integral with a frame having a central opening. The prongs extend across the opening and are supported upon a ledge of the frame. The frame has curved U-shaped downwardly extending edges which are parallel to the prongs.

I United States Patent 1151 3,678,541 Lefkowitz 1 July 25, 1972 154] BUCKLE CLOSURE FOR PLASTIC 3,064,271 11/1962 Kuber ..24/2oo STRAPPING 880,758 3/1903 Rust. ..24/74 Inventor: d m Levmown NY. 129,925 7/ 1872 Brodie ..24/22 [73] Assignee: Delta Strapping Industries, Inc., Wood- Primary Examiner-Bobby R. Gay side, L.l., N.Y. Assistant Examiner-Garry Moore [22] File? 1 97 Attorney-Richards & Geier [2|] App]. No.: 41,984 [57] ABSTRACT A buckle used as a strapping closure includes two parallel [52] US. Cl. .2417, 24/200 tapered prqngs holding the strap. The prongs have adjacent [51] Int. Cl. ..A44b 11/00 open ends while their m ends we fi l connected to [$8] mil GISGIICI! ..24/l98, 197, 200, 22, 23, 74, curved gusset T Bus is integral with a frame hvina cam 24/75 77 tral opening. The prongs extend acres the opening and are supported upon a ledge of the frame. The frame has curved U- B6] Rum CM shaped downwardly extending edges which are parallel to the UNITED STATES PATENTS Prongs' 3,206,816 9/1965 Uilcins et al. ..24l200 1 Claim, 2 Drawing figures BUCKLE CLOSURE FOR PLASTIC STRAPPING This invention relates to a buckle used as a closure for plastic straps wrapped around a package.

The buckle or closure now in general use for plastic strapping is made of a single piece of round wire and requires a four slide press for its manufacture. Practical experience has shown that these closures fail at a load of 30 percent or less of the ultimate strap strength.

An object of the present invention is the provision of a buckle closure for plastic strapping which can be made more economically than existing constructions, which will have a greater holding power and can be more easily operated, particularly as far as the removal of the slack from the strap is concerned.

A more specific object of the present invention is the provision of a novel buckle closure which can be made on a two slide press and which can sustain a load of up to 60 percent of the ultimate strap strength.

Other objects of the present invention will become apparent in the course of the following specification.

In the accomplishment of the objectives of the present invention it was found desirable to provide a buckle closure for plastic strapping which has two parallel slightly tapered prongs used to hold the strap and having adjacent ends attached or integral with a curved gusset. The gusset is integral with a rectangular frame having a central opening located under the prongs and a ledge upon which the free ends of the prongs rest. Opposed edges of the frame extending parallel to the prongs are U-shaped in section and form downwardly located grooves.

The buckle closure of the present invention can be easily made on a two slide press and it can sustain a substantial amount of load exerted upon the strap up to 60 percent of the ultimate strap strength.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawing showing by way of example only, a preferred embodiment of the inventive idea.

In the drawing:

FIG. I is a perspective view of a buckle constructed in accordance with the principles of the present invention.

FIG. 2 is similar to FIG. I but shows the strap connected to the buckle.

The buckle shown in the drawing has two parallel prongs l and II which have the shape of an inverted U in cross-section. The ends 12 and I3 of the prongs l0 and ll are open and are somewhat tapered. This improves the stiffness of the structure and also improves strap threading.

The opposite ends of the prongs l0 and ll are firmly connected or integral with the top portion 14 of a U-shaped gusset IS. The lower portion of the gusset is integral with a substantially rectangular frame 16. The frame l6 has a central rectangular opening 17 across which the prongs l0 and ll extend. Edges l8 and 19 of the frame 16 which extend parallel to the prongs 10 and ll. have the shape of lower grooves with higher inner wall portions. The portion of the frame 16 which is opposed to the gusset 15 has the shape of a higher ledge 20 upon which rest the free ends 12 and 13 of the prongs l0 and ll.

The described buckle is made from a flat rectangular steel plate which is initially treated to provide grooved edges 18 and 19. Then the central opening 17 is cut in the plate and finally the gusset 15 and the prongs 10 and ll are formed.

in use a strap 21 (FIG. 2) is placed around a package (not shown) and then threaded up and around the prongs l0 and II and down through the opening l7. Strap threading is facilitated by the tapered ends [2 and I3 of the prongs; they also improve stiffness. Stiffness is further improved by the provision of the gusset 15.

After the threading of the strap 21 it is necessary to remove slack from the strap by pulling the upper portions 22 of the strap in the direction of arrows 23. The provision of the raised ledge 20 greatly facilitates this removal of slack since it gives the strap more room for movement. The gusset l5 prevents the prongs l0 and 11 from moving in the strap pulling direction and forces the prongs downwardly when tension ls applied. Practical experience has shown that this downward movement is of great importance since it makes it possible for the buckle to withstand the higher load. The curved ends 18 and 19 of the plate 16 also stiffen, straighten and facilitate strap lacing. Finally, the lacing is greatly facilitated by the provision of the central opening 17 in the frame l6.

lclaim:

l. A buckle closure for plastic strapping, comprising a frame having four sides enclosing a rectangular opening. one side of the frame consisting of a U-shaped gusset having an upper portion extending over one edge of the rectangular opening and a lower portion parallel to said upper portion, two other parallel sides of the frame having end portions integral with the lower portion of said gusset and parallel grooves, each of said grooves having a lower outer edge and a higher inner edge constituting an edge of said opening, said grooves extending from said end portions and terminating in curved open ends constituting parts of the fourth side of the frame, said fourth side having a flat ledge portion extending parallel to said gusset and above said parallel frame sides and having opposed ends integral with portions of the inner edges of said grooves, and two parallel prongs extending across said rectangular opening, each of said prongs having the shape of an inverted U in cross section and having one end firmly connected with the upper portion of said gusset and an opposed end which is tapered and lies upon said flat ledge portion of the fourth side of the frame.

0- a e e a 

1. A buckle closure for plastic strapping, comprising a frame having four sides enclosing a rectangular opening, one side of the frame consisting of a U-shaped gusset having an upper portion extending over one edge of the rectangular opening and a lower portion parallel to said upper portion, two other parallel sides of the frame having end portions integral with the lower portion of said gusset and parallel grooves, each of said grooves having a lower outer edge and a higher inner edge constituting an edge of said opening, said grooves extending from said end portions and terminating in curved open ends constituting parts of the fourth side of the frame, said fourth side having a flat ledge portion extending parallel to said gusset and above said parallel frame sides and having opposed ends integral with portions of the inner edges of said grooves, and two parallel prongs extending across said rectangular opening, each of said prongs having the shape of an inverted U in cross section and having one end firmly connected with the upper portion of said gusset and an opposed end which is tapered and lies upon said flat ledge portion of the fourth side of the frame. 